SUMMARY
Although IBS is the most common functional disorder of
alimentary tract in western countries, its pathogenesis is
still not fully understood. It seems that multiple precipitating
factors alter gut motility and visceral perception, resulting
in specific motor function disorders. These disorders
seem to differ between patients presenting with constipation
and those presenting with diarrhea. The most common
motility disorders found in IBS patients include the
frequency of high amplitude propagating contractions
(HAPC), the contractile activity of rectosigmoid, and the
motor function changes after ingestion of food. The presence
of a generalized alimentary tract motility disorder in
IBS, suggests the presence of a systematic neuromuscular
dysfunction. In two-thirds of patients, a disturbance in visceral
perception and visceral hypersensitivity as a response
to either normal, or abnormal stimuli, exists. Despites the
fact that the actual mechanisms responsible for these disorders
are, as yet, partially unknown, there is a body of evidence
that a brain-gut axis dysfunction, further impaired
by psychological stress, may be the leading cause of IBS.
Key words: Irritable bowel syndrome, gastrointestinal motility,
visceral hypersensitivity, visceral perception
(EN)